I have a font which applies Offset Path and Round Corners as a CP. In this font there are two glyphs which produce different results for the same path. In the image attached to this post, the left image here shows what appears in the Preview window in Glyphs, and the right image is the result that is created on export. Note there is no break in the fraction and the numeral four in the exported version, but the fraction bar is broken in the second glyph.
I have attached a Glyphs file containing only these two glyphs. In this example I have decomposed the fraction glyph, just to be sure that it isn’t something to do with components In the original the fraction bar is a component and even as a component Glyphs treats it differently on export.
TEST.zip (2.2 KB)